Biodiversity- short for "biological diversity" - means the diversity of living organisms in all its manifestations: from genes to the biosphere. The issues of study, use and conservation of biodiversity began to be given much attention after the signing by many states of the Convention on Biological Diversity (UN Conference on Environment and Development, Rio de Janeiro, 1992).

There are three main type of biodiversity:

- genetic diversity, reflecting intraspecific diversity and due to the variability of individuals;

- species diversity, reflecting the diversity of living organisms (plants, animals, fungi and microorganisms). At present, about 1.7 million species have been described, although their total number, according to some estimates, is up to 50 million;

- diversity of ecosystems covers differences between ecosystem types, habitat diversity and ecological processes. They note the diversity of ecosystems not only in terms of structural and functional components, but also in terms of scale - from microbiogeocenosis to the biosphere;

All types of biological diversity interconnected: Genetic diversity ensures species diversity. The diversity of ecosystems and landscapes creates conditions for the formation of new species. An increase in species diversity increases the overall genetic potential of the living organisms of the Biosphere. Each species contributes to diversity - from this point of view, there are no useless and harmful species.

Distribution species on the surface of the planet unevenly. Species diversity in natural habitats is highest in the tropical zone and decreases with increasing latitude. The richest ecosystems in species diversity are tropical rainforests, which occupy about 7% of the planet's surface and contain more than 90% of all species.

In the geological history of the Earth in the biosphere, there has been a constant emergence and extinction of species All species have a finite lifetime. The extinction was compensated by the emergence of new species, and as a result, the total number of species in the biosphere increased. The extinction of species is a natural process of evolution that occurs without human intervention.

Currently, under the influence of anthropogenic factors, there is reduction biological diversity due to the elimination (extinction, destruction) of species. In the last century, under the influence of human activity, the rate of extinction of species has exceeded the natural rate by many times (according to some estimates, 40,000 times). There is an irreversible and uncompensated destruction of the unique gene pool of the planet.

Elimination of species as a result of human activities can occur in two directions- direct extermination (hunting, fishing) and indirect (habitat destruction, disturbance of trophic interactions). Overfishing is the most obvious direct cause of the direct decline of species, but it is much less likely to contribute to extinction than indirect causes of habitat change (eg, chemical pollution of a river or deforestation).

Diversity of biotic cover, or biodiversity, is one of the factors for the optimal functioning of ecosystems and the biosphere as a whole. Biodiversity ensures the resilience of ecosystems to external stresses and maintains a dynamic balance in them. The living from the non-living, first of all, differs by several orders of magnitude in its great diversity and the ability not only to preserve this diversity, but also to significantly increase it in the course of evolution. In general, the evolution of life on Earth can be viewed as a process of structuring the biosphere, a process of increasing the diversity of living organisms, forms and levels of their organization, a process of the emergence of mechanisms that ensure the stability of living systems and ecosystems in the constantly changing conditions of our planet. It is the ability of ecosystems to maintain balance, using the hereditary information of living organisms for this, that makes the biosphere as a whole and local ecosystems material-energy systems in the full sense.

In this photo we see many types of plants growing together in a meadow in the floodplain of the river. Budyumkan in the southeast of the Chita region. Why did nature need so many species in one meadow? This is what this lecture is about.

Russian geobotanist L.G. Ramensky in 1910 he formulated the principle of ecological individuality of species - a principle that is the key to understanding the role of biodiversity in the biosphere. We see that many species live together in each ecosystem at the same time, but we rarely think about the ecological meaning of this. Ecological individuality plant species living in the same plant community in the same ecosystem allows the community to quickly rebuild when external conditions change. For example, in a dry summer in this ecosystem, the main role in ensuring the biological cycle is played by individuals of species A, which are more adapted to life with a moisture deficit. In a wet year, individuals of species A are not at their optimum and cannot ensure the biological cycle in the changed conditions. In this year, individuals of species B begin to play the main role in ensuring the biological cycle in this ecosystem. The third year turned out to be cooler; under these conditions, neither species A nor species B can ensure the full use of the ecological potential of this ecosystem. But the ecosystem is rapidly rebuilding, as it contains individuals of species B, which do not need warm weather and photosynthesize well at low temperatures.

Each species of living organisms can exist in a certain range of values ​​of external factors. Outside these values, individuals of the species die. In the diagram, we see the limits of endurance (limits of tolerance) of the species according to one of the factors. Within these limits, thereoptimum zone, the most favorable for the species, and two zones of oppression. Rule L.G. Ramensky on the ecological individuality of species argues that the limits of endurance and optimum zones in different species living together do not coincide.

In nature, we find a lot of factors or mechanisms that provide and maintain a high species diversity of local ecosystems. First of all, such factors include excessive reproduction and overproduction of seeds and fruits. In nature, seeds and fruits are produced hundreds and thousands of times more than is necessary to make up for the natural loss due to premature death and dying of old age.

Thanks to adaptations for distributing fruits and seeds over long distances, the rudiments of new plants fall not only on those areas that are favorable for their growth now, but also on those areas whose conditions are unfavorable for the growth and development of individuals of these species. Nevertheless, these seeds germinate here, exist in a depressed state for some time and die. This happens as long as environmental conditions are stable. But if the conditions change, then the seedlings of species unusual for this ecosystem, previously doomed to death, begin to grow and develop here, going through a full cycle of their ontogenetic (individual) development. Ecologists say that in nature there is powerful pressure of diversity of life to all local ecosystems.

General land cover gene pool- its flora-local ecosystems of this region are used most fully due to the pressure of biodiversity. At the same time, local ecosystems in terms of species become richer. During their formation and rearrangement, the ecological selection of suitable components is carried out from a larger number of applicants whose diagerms have got into a given habitat. Thus, the probability of forming an ecologically optimal plant community increases.

Thus, the stability factor of a local ecosystem is not only the diversity of species living in this local ecosystem, but also the diversity of species in neighboring ecosystems, from which the introduction of diagerms (seeds and spores) is possible. This applies not only to plants that lead an attached lifestyle, but even more so to animals that can move from one local ecosystem to another. Many animal individuals, not belonging specifically to any of the local ecosystems (biogeocenoses), nevertheless play an important ecological role and participate in ensuring the biological cycle in several ecosystems at once. Moreover, they can alienate biomass in one local ecosystem, and throw out excrement in another, stimulating the growth and development of plants in this second local ecosystem. Sometimes such a transfer of matter and energy from one ecosystem to another can be extremely powerful. This flow connects completely different ecosystems.

Diversity of species and diversity of life forms or ecobiomorph are not the same thing. I will demonstrate this with an example. In the meadow, species, genera and families of plants can live 2-3 times more than in the dark coniferous forest. However, in terms of ecobiomorphs and synusia, it turns out that the biodiversity of the dark coniferous forest as an ecosystem is much higher than the biodiversity of the meadow as an ecosystem. In the meadow, we have 2-3 classes of ecobiomorphs, and in the dark coniferous forest, 8-10 classes. There are many species in the meadow, but all of them belong either to the class of ecobiomorphs, perennial mesophytic summer-green grasses, or to the class of annual grasses, or to the class of green mosses. In the forest, different classes of ecobiomorphs are: dark coniferous trees, deciduous trees, deciduous shrubs, deciduous shrubs, perennial mesophytic summer green grasses, green mosses, epigeic lichens, epiphytic lichens.

The biodiversity of organisms in the biosphere is not limited to the diversity of taxa and the diversity of ecobiomorphs of living organisms. For example, we can get into an area that is entirely occupied by one local elemental ecosystem - a raised swamp, or a damp alder forest at the mouth of a large river. In another area on the same territory, we will meet at least 10-15 types of local elementary ecosystems. Ecosystems of coniferous-broad-leaved forests at the bottom of river valleys are regularly replaced here by ecosystems of cedar-oak mixed-shrub forests on the southern gentle slopes of mountains, larch-oak mixed-grass forests on the northern gentle slopes of mountains, spruce-fir forests in the upper part of the northern steep slopes of mountains and ecosystems steppe meadows and clump vegetation on the steep southern slopes of the mountains. It is easy to understand what is intra-landscape diversity of ecosystems determined not only by the diversity of their constituent species and ecobiomorphs, but also variety of ecological landscape background associated primarily with the diversity of landforms, the diversity of soils and their underlying rocks.

The processes of extinction of species in the biosphere are compensated by the processes of speciation. If the balance of these two processes is upset in favor of extinction, then the Earth will most likely face the fate of Venus - that is, an atmosphere of carbon dioxide and water vapor, a surface temperature of about +200 degrees Celsius, evaporated oceans and seas. Life on a protein basis in such conditions, of course, is simply impossible. Having become a powerful geological force, humanity must take responsibility not only for the future of its children and grandchildren, but also for the future of the entire biosphere. And this future will largely depend on how far the process of extinction of species in the Earth's biosphere lags behind the process of formation of new species.

For the accounting species that are on the verge of extinction, many countries create Red Books - lists of rare and endangered species of living organisms. To preserve and maintain biological diversity, specially protected natural areas are created - protected areas (reserves, national parks, etc.), genetic data banks. The preservation of an individual species is possible only if its habitat with the entire complex of species included in it, as well as climatic, geophysical and other conditions, is protected. A special role is played by the conservation of environment-forming species (edificatory species), which form the internal environment of the ecosystem. The creation of protected areas is aimed at protecting not only individual species, but also entire complexes and landscapes.

Reserves also serve to evaluate and monitoring state of biodiversity. There is no unified system for monitoring the state of biodiversity in Russia today. The most complete and permanent control over changes in biodiversity components is carried out in reserves. Every year, reserves prepare reports on the state of ecosystems ("Chronicles of Nature") - summaries of data on the state of protected areas, protected populations of plants and animals. Some reserves have been keeping "Chronicles of Nature" for more than 50 years, which include continuous series of data on the number of animals, biological diversity, ecosystem dynamics, as well as data on climate observations.

Part of the reserves of Russia (18) is part of the international network of biosphere reserves, specially created to monitor the state of biodiversity, climatic, biogeochemical and other processes on the scale of the Biosphere.

reasons need conservation biodiversity many: the need for biological resources to meet the needs of mankind (food, materials, medicines, etc.), ethical and aesthetic aspects (life is valuable in itself), etc. However, the main reason for the conservation of biodiversity is that it plays a leading role in ensuring the sustainability of ecosystems and the Biosphere as a whole (absorption of pollution, climate stabilization, provision of conditions suitable for life). Biodiversity performs a regulatory function in the implementation of all biogeochemical, climatic and other processes on Earth. Each species, no matter how insignificant it may seem, contributes to ensuring the sustainability of not only the “native” local ecosystem, but the Biosphere as a whole.

SOIL ECOLOGY

LECTURE № 8,9,10

SUBJECT:

Ecological functions of soils. Biochemical transformation of the upper layers of the lithosphere. Transformation of surface waters into groundwater and participation in the formation of river runoff. Regulation of the gas regime of the atmosphere . Ecological function of soils. Participation of soils in the formation of the geochemical flow of elements.

The soil cover forms one of the geophysical shells of the Earth - the pedosphere. The main geospheric functions of the soil as a natural body are due to the position of the soil at the junction of animate and inanimate nature. And the main one is the provision of life on Earth. It is in the soil that terrestrial plants take root, small animals, a huge mass of microorganisms live in it. As a result of soil formation, it is in the soil that water and mineral nutrition elements that are vital for organisms are concentrated in the forms of chemical compounds available to them. Thus, soil is a condition for the existence of life, but at the same time soil is a consequence of life on Earth.

The global functions of soils in the biosphere are based on the following fundamental qualities. First, the soil serves as a habitat and physical support for a huge number of organisms; secondly, the soil is a necessary, irreplaceable link and regulator of biogeochemical cycles; practically, the cycles of all biogens are carried out through the soil.

Signed in June 1992 in Rio de Janeiro, the International Convention on Biological Diversity can be seen mainly as an expression of general concern about the loss of what cannot be restored - species of living beings, each of which occupies a certain place in the structure of the biosphere. Will a united humanity be able to preserve biodiversity? This largely depends on the attention of historical processes and the current factors that have influenced the development of biological diversity as we know it, or, more precisely, we know it to a small extent.

We don't know how many species there are. In the rainforest canopy alone, there can be up to 30 million, although most researchers accept a more conservative figure of 5-6 million. There is only one way to save them - by protecting the tropical forest as an ecosystem from clear-cutting and pollution. In other words, in order to preserve species diversity, it is necessary first of all to take care of the diversity of a higher level - ecosystems. At this level, tundra and polar deserts deserve no less attention than tropical forests, with which they are comparable in spatial parameters as structural divisions of the biosphere, although they are much poorer in species.

Biological diversity (BD) is a variety of forms and processes in the organic world, manifested at the molecular genetic, population, taxonomic and cenotic levels of the organization of the living. Although the levels of organization are named here in their traditional bottom-up sequence (each subsequent level includes the previous ones), this order of consideration does little to understand the nature of BR. If we are interested in the reasons for the emergence of BR (according to religious beliefs, BR arose as a result of a creative act, the logic of which should also be available to a reasonable being), then it is better to move from top to bottom, starting with the biosphere - the earth's shell containing organisms and their metabolic products. The biosphere is superimposed on the physical shells of the Earth - the earth's crust, hydrosphere and atmosphere, the composition of which is largely determined by the biogenic circulation of substances.

Each of these shells, in turn, is heterogeneous in physical properties and chemical composition in the direction of gravity and rotational forces, which determine the division into the troposphere and stratosphere, oceans, marginal seas and inland water bodies, continents with their geomorphological heterogeneities, etc. Heterogeneity of conditions It is also created by the uneven distribution of incoming solar energy over the earth's surface. The latitudinal climatic zonality on the continents is complemented by climatic vectors directed from the coast inland. A regular change in conditions in terms of height above sea level and depth creates a vertical zonality, which is somewhat similar to latitudinal zonality. Life is superimposed on all these heterogeneities, forming a continuous film that does not break even in deserts.

Continuous living cover is the result of long evolution. Life arose at least 3.5 billion years ago, but for about 6/7 of this time, the land remained almost lifeless, as did the ocean depths. The expansion of life was carried out by adapting to different conditions of existence, differentiation of life forms, each of which, within its habitats, is most efficient in the use of natural resources (you can try to replace all diversity with one species, as modern man does, in essence, but the efficiency of use resources of the biosphere will sharply decrease as a result).

Conditions changed not only in space, but also in many respects similarly in time. Some forms of life have proven to be more adaptable to change than others. Life was interrupted in separate zones, but, at least in the last 600 million years, forms were constantly found that could survive the crisis and fill the gaps that had formed (remains of more tree organisms are not numerous, and we are not sure that during the Precambrian history life did not interrupted). Thus, BR ensures the continuity of life in time.

As life covered the surface of the planet with a continuous film, the organisms themselves increasingly acquired the importance of the main factor in the formation of living space, the functional structure of the biosphere, associated with the biogenic transformation of matter and energy carried out within its boundaries, the effectiveness of which is ensured by the distribution of roles between organisms, their functional specialization. . Each functional cell of the biosphere - an ecosystem - is a local set of organisms interacting in the process of biogenic circulation and components of their environment. The spatial expression of an ecosystem can be a landscape, its facies (in this case, they speak of a biogeocenosis, which, according to V.N. Sukachev, includes a geological substrate, soil, vegetation, animal and microbial population), any component of the landscape (water body, soil, plant community) or a single organism with its external internal symbionts.

The functional space of an ecosystem (multidimensional, in contrast to the physical one) is subdivided into ecological niches corresponding to the distribution of roles between organisms. Each niche has its own life form, a kind of role that determines the main morphophysiological features of organisms and depends on them in feedback. The formation of an ecological niche is a mutual process in which the organisms themselves play an active role. In this sense, niches do not exist apart from life forms. Nevertheless, the predetermination of the ecosystem structure, associated with its functional purpose, makes it possible to recognize “empty niches” that must be filled in order for the structure to be preserved.

Thus, biological diversity is necessary to preserve the functional structure of the biosphere and its constituent ecosystems.

A stable combination of functionally interconnected life forms forms a biotic community (biocenosis), the composition of which is the more diverse, the more complex the structure of the ecosystem, and this latter depends mainly on the stability of the processes occurring in the ecosystem. So, in the tropics, the diversity is higher, since photosynthesis is not interrupted during the year.

Another important function of the BR is associated with the development and restoration of the community - reparation. Species perform different roles in the course of autogenetic succession - a change in developmental stages from pioneer to climax. Pioneer species are undemanding in terms of quality and sustainability of the environment and have a high reproductive potential. Stabilizing the environment, they gradually give way to more competitive species. This process goes to the final phase (climax), which is capable of holding the territory for a long time, being in a state of dynamic equilibrium. Since a variety of external influences constantly disrupt succession, monoclimax most often remains a theoretical possibility. Stages of development are not completely replaced, but coexist in complex successional systems, providing them with the opportunity to recover from destructive impacts. The recovery function is usually performed by rapidly breeding pioneer species.

It would be an exaggeration to claim that we can accurately determine the functional purpose of each species in any of the many ecosystems. The removal of a species also does not always lead to their destruction. Much depends on the complexity of the ecosystem (in Arctic communities with a relatively simple trophic structure, the share of each species is much higher than in the tropics), its successional and evolutionary stages of development, which determine the overlap (duplication) of ecological niches and the redundancy of structural elements. At the same time, duplication and redundancy in systems theory are considered as stability factors, i.e., they have a functional meaning.

All of the above allows us to conclude that the random element in the BR does not play a significant role. BR is functional. Each of its components is formed by the system in which it is included, and in turn, according to the feedback principle, determines the features of its structure.

In general, BR reflects the spatio-temporal and functional structure of the biosphere, providing: 1) the continuity of the living cover of the planet and the development of life in time, 2) the efficiency of biogenic processes in the ecosystem, 3) the maintenance of dynamic balance and the restoration of communities.

These appointments determine the structure of the BR at all hierarchical levels of its organization.

^ Structure of biological diversity

The genetic material in most organisms is contained in huge DNA and RNA molecules, filamentous polynucleotides that can look like a ring chromosome or a set of linear chromosomes, which are extremely diverse in terms of total DNA content, number, shape, development of various types of heterochromatin. and also by the types of restructurings in which they participate. All this creates a variety of genomes as complex systems that make up - in higher organisms - from tens of thousands of discrete genetic elements, or genes. Their discreteness is structural in nature (for example, unique or repeatedly repeated nucleotide sequences) or expressed functionally, as in protein-coding, reproduced as a whole, co-managed, involved in cross-exchange between paired chromosomes, and, finally, moving through the genome elements. When molecular mechanisms were not understood, the idea of ​​a gene was abstract and endowed with all these functions, but now it is known that they are performed by structurally different genetic particles that make up a variety of gene types. As a result of changes in the nucleotide composition, or mutations, similar sections of paired chromosomes have a different structure. Such sites-chromosomal loci, known in several states, are called polymorphic. Genetic polymorphism is transformed into protein polymorphism, which is studied by molecular genetic methods, and, ultimately, into the genetic diversity of organisms. At these derived levels, the diversity of genes appears in an indirect form, since traits are determined by the genetic system, and not by individual genes.

N. I. Vavilov showed on extensive material that the diversity of hereditary characters in closely related species is repeated with such accuracy that it is possible to predict the existence of a variant not yet found in nature. Thus, the orderliness of genetic variability (contrary to the ideas about the unpredictability of mutations) was revealed, in which the properties of the genome as a system are manifested. This fundamental generalization, formulated as the law of homological series, underlies the study of the BR structure.

The transfer of hereditary information from one generation to another is carried out in the process of reproduction of organisms, which can be asexual, sexual, in the form of alternation of asexual and sexual generations. Superimposed on this diversity are differences in the mechanisms of sex determination, sex separation, etc. Suffice it to think of fish species that consist of some females (reproduction is stimulated by males of other species) or the ability of females to turn into males, if there are not enough of them, to imagine diversity. reproduction processes in vertebrates, not to mention organisms such as fungi, where it is many times higher.

Organisms involved in reproduction constitute the reproductive resources of a species, which are structured according to the diversity of reproductive processes. The units of the reproduction system are demo-local groupings of interbreeding individuals and populations - larger groupings within a landscape or ecosystem. Accordingly, geographical and coenotic populations are distinguished, although their boundaries may coincide.

In the process of reproduction, recombination of genes takes place, which, as it were, belong to the population as a whole, constituting its gene pool (the gene pool is also spoken of in a broader sense as the totality of fauna or flora genes; this is partly justified, since at least episodic gene exchange is possible during hybridization or transfer of genetic material by microorganisms). The unity of a population, however, is ensured not only by a common gene pool, but also by entry into geographic or biological systems of a higher level.

Populations of neighboring landscapes or ecosystems always show certain differences, although they may be so close that taxonomists consider them to be the same species. In essence, a species is a set of populations of a number of historically interconnected landscape and (or) cenotic complexes. The integrity of a species as a system is due to the historical community of its constituent populations, the flow of genes between them, as well as their adaptive similarity due to close living conditions and coenotic functions. The latter factors are also effective in relation to asexual organisms, determining the universal significance of a species as the main unit of biological diversity (the often encountered hypertrophied idea of ​​sexual gene transfer as the most significant criterion for a biological species makes us see it as a category peculiar exclusively to dioecious organisms, which contradicts taxonomic practice).

The properties of a species are determined, as we have already noted, by that part of the ecological space that it steadily occupies, i.e. ecological niche. At the early stages of the development of a biological community, there is a significant overlap of ecological niches, but in the established coenotic system, species, as a rule, occupy rather isolated niches, however, a transition from one niche to another in the growth sling is possible (for example, in attached forms with mobile larvae) , entry into various communities in some cases as a dominant, in others - a secondary species. There are certain disagreements among specialists regarding the nature of biotic communities - either random collections of species that have found suitable conditions for themselves, or integral systems like organisms. These extreme points of view, most likely, reflect the diversity of communities that are completely unequal in their systemic properties. Also, species are sensitive to their coenotic environment to varying degrees, from independent (conditionally, since they belong to communities of higher ranks) to “true”, according to which associations, unions and classes are distinguished. This classificatory approach was developed in Central Europe and is now widely accepted. A rougher "physiognomic" classification according to the dominant species is adopted in the northern countries, where relatively homogeneous forest formations still occupy vast areas. Within landscape-climatic zones, groups of characteristic formations form the biomes of tundra, taiga forests, steppes, etc.) - the largest landscape-coenotic subdivisions of the biosphere.

^ Evolution of biological diversity

BR develops into a process of interaction between the biosphere and the physical shells of the Earth, on which it is superimposed. The movement of the earth's crust and climatic events cause adaptive changes in the macrostructure of the biosphere. For example, a glacial climate is characterized by a higher diversity of biomes than a non-glacial one. Not only polar deserts, but also tropical rainforests owe their existence to the atmospheric circulation system, which is formed under the influence of polar ice (see above). The structure of biomes, in turn, reflects the contrast of relief and climate, the diversity of geological substrates and soils - the heterogeneity of the environment as a whole. The species diversity of the communities that make up them depends on the fragmentation of the division of the ecological space, and this latter depends on the stability of conditions. In general, the number of species is s==g – py, where a is the diversity of species in communities, p is the diversity of communities, and y is the diversity of biomes. These components change with a certain frequency, rebuilding the entire BR system. For example, in the Mesozoic (glacier-free climate), the diversity of plants approximately corresponds to the modern one in similar formations of hard-leaved shrubs and summer-green forests, but the total number of species is about half that of the modern one due to the low diversity.

Genetic diversity in turn changes as a function of the adaptive strategy of the species. The fundamental property of a population is that, theoretically, during its reproduction, the frequencies of genes and genotypes are preserved from generation to generation (the Hardy-Weinberg rule), changing only under the influence of mutations, genetic drift and natural selection. Variants of the structure of genetic loci that arise as a result of mutations - alleles - often do not have an adaptive effect and constitute a neutral part of polymorphism, subject to random changes - gene drift, and not directed selection - hence the model of "non-Darwinian" evolution.

Although the evolution of population diversity is always the result of drift and selection, their relationship depends on the state of ecosystems. If the ecosystem structure is disturbed, stabilizing selection is weakened, then evolution acquires an incoherent character: genetic diversity increases due to mutagenesis and drift without a corresponding increase in species diversity. Ecosystem stabilization directs the strategy of populations towards a more efficient use of resources. At the same time, the heterogeneity (“coarse-grain”) of the environment, which is more pronounced, becomes a factor in the selection of genotypes that are most adapted to the “grain” of the landscape-coenotic mosaic. At the same time, neutral polymorphism acquires an adaptive value, the ratio of drift and selection changes in favor of the latter. The progressive differentiation of demes becomes the basis for the fragmentation of species. Evolving steadily over millennia, these processes create exceptionally high species diversity.

The system thus directs the evolution of its constituent organisms (to avoid misunderstandings, we note that there are no organisms that are not members of the coenotic systems: even the so-called coenophobic groups that disrupt the development of the community are included in systems of a higher rank).

The end-to-end evolutionary trend is one of increasing diversity, interrupted by sharp declines as a result of mass extinctions of species (about half at the end of the dinosaur era, 65 million years ago). The frequency of extinction coincides with the activation of geological processes (movement

Earth's crust, volcanism) and climatic changes, pointing to a common cause.

In the past, J. Cuvier explained such crises by the direct destruction of species as a result of marine transgressions and other catastrophes. Charles Darwin and his followers did not attribute crises at all, attributing them to the incompleteness of the geological Chronicle. Crises are now beyond doubt; moreover, we are experiencing one of them. A general explanation of crises is given by the ecosystem theory of evolution (see above), according to the second, the reduction in diversity occurs due to the stability of the environment, which determines the trend towards

simplifying the structure of ecosystems (some species are redundant),

interruption of successions (types of the final-climax - stages are doomed to extinction) and

an increase in the minimum size of the population (in a stable environment, a small number of individuals ensures reproduction, a “dense packing” of species is possible, but in a crisis a small population that is incapable of rapid growth can easily disappear).

These patterns are also valid for the anthropogenic crisis of our days.

^ Human Impact on Biodiversity

The direct ancestors of man appeared about 4.4 million years ago, at the beginning of the Gilbert paleomagnetic epoch, marked by the expansion of glaciation in the Antarctic, aridization and the spread of herbaceous vegetation in low latitudes. The habitat, borderline between the tropical forest and the savannah, the relatively weak specialization of the teeth, the anatomy of the limbs, adapted both to movement in open areas and to tree acrobatics, testify to the wide ecological louse of the African Australopithecus, the oldest representative of this group. In the future, evolution enters a coherent phase, and species diversity increases. Two lines of adaptive radiation - graceful and massive Australopithecus - developed along the path of food specialization, in the third - Homo labilis - at the level of 2.5 million years, signs of tool activity appeared as a prerequisite for expanding the food niche.

The latter turned out to be more promising in the unstable conditions of the Ice Age, the crisis phases of which correspond to the wide distribution of polymorphic species of Homo erectus and later Homo sapiens with a discrepancy between high genetic and low species diversity, characteristic of incoherent evolution. Each of them

Then it entered the phase of subspecific differentiation. About 30 thousand years ago, the specialized Neanderthal subspecies of the "reasonable" was supplanted by the nominative subspecies, the fragmentation of which was already proceeding along the line of cultural rather than biological evolution. Wide adaptive capabilities provided him with relative independence from local ecosystems, which has recently developed into cenophobia. As we have already noted, cenophobia is possible only up to a certain level of the hierarchy of natural systems. Cenophobia towards the biosphere as a whole dooms the species to self-destruction.

A person has an impact on all factors of BD - spatio-temporal heterogeneity of conditions, the structure of ecosystems and their stability. Disturbance of the climax community as a result of logging or fires can give some increase in species diversity due to pioneer and succession species. Spatial heterogeneity in some cases increases (for example, there is a dismemberment of vast forest tracts, accompanied by a certain increase in species diversity). More often, a person creates more homogeneous conditions. This is expressed in the leveling of the relief (in urbanized areas), deforestation, plowing up steppes, draining swamps, introducing alien species that are crowding out native ones, etc.

The influence of man on temporal factors is expressed in the multiple acceleration of natural processes, such as desertification or drying up of inland seas (for example, the Aral Sea, which in the past has repeatedly dried up without human intervention). Human impact on the global climate destabilizes biospheric rhythms and creates a general prerequisite for simplifying the structure of terrestrial and aquatic ecosystems, and, consequently, for the loss of BR.

Over the past two decades, forests have been reduced by almost 200 million hectares, and now the damage is about 1% of the remaining area per year. These losses are distributed very unevenly: the greatest damage was done to the tropical forests of Central America, Madagascar, Southeast Asia, but also in the temperate zone such forest formations as redwood in North America and China (metasequoia), Manchurian black fir forests in Primorye, etc. are on the verge of extinction. Almost no undisturbed habitats remain within the steppe biome. In the United States, more than half of the wetlands have been lost, in Chad, Cameroon, Nigeria, India, Bangladesh, Thailand, Vietnam, and New Zealand - more than 80%.

The loss of species due to habitat disturbance is difficult to assess, since the methods of accounting for species diversity are very imperfect. Assuming a "moderate" estimate of insect diversity of 5 million species for tropical forests and a number of species proportional to the fourth power of area, the loss due to deforestation would be 15,000 per year. Actual losses may differ significantly from the calculated ones. For example, in the Caribbean, no more than 1% of primary forests remain, but the diversity of native bird species has declined by only 11%, as many species have survived in secondary forests. Even more problematic is the assessment of the reduction in the BD of soil biota, which reaches 1000 species of invertebrates per sq. km. m. The loss of soil cover as a result of erosion is estimated in total at 6 million hectares per year - about 6 * 107 species can live in this area.

Probably, the most significant loss of species diversity is associated with the economic development and pollution of ecosystems, which are characterized by a particularly high level of endemism. These include hard-leaved formations of the Mediterranean and Kalekoy province in southern Africa (6000 endemic species), as well as rift lakes (Baikal - about 1500 endemics, Malawi - more than 500).

According to (McNeely, 1992), the loss of species diversity by groups since 1600 is:

Disappeared under threat

Higher plants 384 species (0.15%) 18699 (7.4%)

Pisces 23 -»- (0.12%) 320 (1.6%)

Amphibians 2-»-(0.05%) 48(1.1%)

Reptiles 21 -»- (0.33%) 1355 (21.5%)

Birds 113-»- (1.23%) 924 (10.0%)

Mammals 83 -»- (1.99%) 414 (10.0%)

Violation of the structure and function of ecosystems is associated with their use as raw materials, recreational and deposit (for waste disposal) resources, and raw and deposit use can give directly opposite results. Thus, overgrazing, the removal of canopy-forming trees or game animals disrupt the trophic structure and often return the ecosystem to the early stages of development, delaying succession. At the same time, the flow of organic pollutants into water bodies accelerates succession, passing the ecosystem through a eutrophic state to a hypertrophic one.

The size of the human population does not depend much on the size of the exterminated species, therefore, the feedback in the “predator-prey” system is violated, and a person gets the opportunity to completely exterminate one or another type of prey. In addition, in his role as a superpredator, a person exterminates not the weak and sick, but, on the contrary, the most complete individuals (this also applies to the practice of loggers to cut down the most powerful trees in the first place).

However, indirect damage from impacts that disrupt the balanced relationships and processes in ecosystems and thereby change the direction of species evolution is of greatest importance. Evolutionary changes occur as a result of mutagenesis, genetic drift and natural selection. Radiation and chemical pollution have a mutagenic effect. Withdrawal of biological resources - a significant part of natural populations - turns into a gene drift factor, forcing natural population fluctuations, loss of genetic diversity and, giving an advantage to genotypes with accelerated puberty and high reproductive potential (because of this, indiscriminate removal usually leads to accelerated puberty and shredding ). The direction of natural selection can change under the influence of a variety of biological, chemical. physical (noise, electromagnetic, etc.) pollution. Biological pollution - the deliberate or accidental introduction of alien species and biotechnological products (including laboratory strains of microorganisms, artificial hybrids and transgenic organisms) - is a common factor in the loss of natural BR. The most famous examples are the introduction of placentals into Australia (actually a reintroduction, since they lived on this continent many millions of years ago), elodea into the reservoirs of Eurasia, ctenophores into the Sea of ​​Azov, amphipods Corophium cnrvispinHm into the Rhine from the Ponto-Caspian region (from the first appearance in In 1987, the number of this species increased to 100 thousand individuals per 1 sq.m., competing with local species of zoobenthos, which serve as food for commercial fish and waterfowl). Biological pollution is undoubtedly facilitated by changes in habitats as a result of physical and chemical impacts (increase in temperature and salinity, eutrophication in the case of the introduction of amphipod-thermophilic filter feeders),

In some cases, exposure causes a chain reaction with far-reaching consequences. For example, the entry of eutrophic substances into coastal waters from the continent and from mari culture causes dinoflaellate blooms, secondary pollution with toxic substances, the death of cetaceans, and an increase in the solubility of carbonates, the death of corals and other skeletal forms of benthos. Acid-forming pollution of water bodies, in addition to a direct impact on respiration (deposition of aluminum on the gills) and the reproductive function of amphibian fish, threatens the extinction of many species of aquatic vertebrates and semiaquatic birds due to a decrease in the biomass of larvae of stoneflies, mayflies, and chironomids.

The same factors change the ratio of genotypes in animal and plant populations, giving an advantage to those who are more resistant to various types of stress.

Pollution also becomes a powerful factor in natural selection. A classic example is the increase in the frequency of the melanistic form of Biston betularia butterflies in industrial areas, which was tried to be explained by the fact that on soot-covered trunks they are less noticeable to birds than light forms. This now textbook explanation seems naive, since melanistic forms appear to be more resistant to pollution in many species, including domestic cats and humans. This example warns against simplistic notions of human impact on BR.

^ Biodiversity Conservation

In ancient times, as we have already noted, totemism and the religious ideas that grew out of it contributed to the preservation of individual species and their habitats. We owe the preservation of such relics as ginkgo mainly to the religious rituals of the eastern peoples. In North America, European Colonists took over from local tribes their normative attitude towards nature, while in European feudal countries nature was preserved mainly as royal hunting grounds and parks, with which the aristocracy protected itself from too close contact with the common people.

In early democracies, moral and aesthetic motives were supplanted by economic ones, which often came into conflict with the preservation of BR. The utilitarian attitude to nature acquired especially ugly forms in totalitarian countries. P. A. Manteifel, expressing the official attitude, wrote in 1934: “These groups (of animals) have developed without the influence (will) of man and do not correspond in the majority to the economic effect that could be obtained with a rational change in zoological boundaries and communities, and therefore we put forward the question of the reconstruction of the fauna, where, in particular, the artificial migration of animals should take a prominent place.

Nevertheless, the new aristocracy - the party leadership and persons close to it - also needed protected hunting grounds, which were called hunting reserves.

In the 1960s, the reserves underwent a two-fold reduction due to the extensive development of the economy. In addition, the allotment of huge areas for monoculture had an extremely unfavorable effect on the state of the BR. In the early 1980s, to fulfill the "food program", roadsides, borders and inconveniences were plowed, depriving wild species of their last refuges in the developed areas.

Unfortunately, these trends were further developed during the period of perestroika in connection with the transfer of waste land to farmers and the development of private enterprise in the conditions of legislative chaos. Self-occupation of land for vegetable gardens, deforestation in green belts around cities, illegal extraction of rare species and free sale of biological resources have become common practice. The reserves have never been very popular on the ground and with the weakening of control they are subject to increasing pressure from economic structures and poachers. The development of international tourism is damaging territories that were previously protected as sensitive. These include military training grounds and border lands (in Germany, the 600x5 km exclusion zone has turned into a kind of reserve over the years of confrontation, which is now trampled down by crowds of tourists).

At the same time, there is reason to hope for an improvement in the situation (and, in particular, the transformation of former regime areas into nature reserves) due to the universal recognition of the priority of conservation of the BR. The immediate task is to develop and strengthen national programs. Let us note some fundamental points arising in this connection. Inventory and protection of biological diversity. Identification of the species structure in many cases is necessary for the organization of protection. For example, the New Zealand tuatara (tuatara), the only representative of the oldest group of beak-headed reptiles, has been protected since 1895, but only recently it has become clear that there are two species of tuatara with subspecies, one of the species, S-guntheri and a subspecies of the other, S.punctata reischeki were on the verge of extinction, and ten out of forty populations have already disappeared; there is still a lot of work ahead of traditional systematics in the field of BR conservation.

At the same time, the idea quite often expressed that in order to preserve it is necessary, first of all, to inventory all taxonomic diversity, has a somewhat demagogic connotation. There can be no question of describing all the multimillion-dollar diversity of species in the foreseeable future. Species disappear without ever receiving the attention of a taxonomist. A more realistic approach is to develop a sufficiently detailed syntaxonomic classification of communities and organize in situ protection on this basis. The protection of the top-level system to a certain extent ensures the preservation of its components, some of which we do not know or know in the most general terms (but at least we do not exclude the possibility of learning in the future). In the following sections, we will consider some of the principles for organizing protection on a syntaxonomic basis to cover all or most of the taxonomic diversity.

Combining human rights with animal rights. Recognition of animal rights does not mean rejection of their use. In the end, people are also used legally. It cannot be denied that it is fair that a man has more rights than an animal, just as an adult has more rights than a child. However, without falling into environmental terrorism, which is mostly provocative, it should still be recognized that reasonable use has nothing to do with killing for pleasure or on a whim, as well as with cruel experimentation, which, moreover, is mostly senseless, according to

Which spread and live in various natural zones. Such biodiversity is not the same in different climatic conditions: some species adapt to the harsh conditions of the arctic and tundra, others learn to survive in deserts and semi-deserts, others love the warmth of tropical latitudes, others inhabit forests, and still others spread over wide expanses of the steppe. The state of species that exists on Earth at the moment was formed over 4 billion years. However, one of them is the reduction of biodiversity. If it is not solved, then we will forever lose the world that we know now.

Causes of biodiversity decline

There are many reasons for the decline in animal and plant species, and all of them directly or indirectly come from people:

• expansion of the territories of settlements;
• regular emissions of harmful elements into the atmosphere;
• transformation of natural landscapes into agricultural objects;
• the use of chemicals in agriculture;
• pollution of water bodies and soil;
• construction of roads and provision of communications;
• , requiring more food and territories for life;
• experiments on crossing plant and animal species;
• destruction of ecosystems;
• caused by people.

Of course, the list of reasons can go on. Whatever people do, they affect the reduction of the areas of flora and fauna. Accordingly, the life of animals changes, and some individuals, unable to survive, die prematurely, and the number of populations is significantly reduced, often leading to the complete extinction of the species. Much the same thing happens with plants.

The value of biodiversity

The biological diversity of different forms of life - animals, plants and microorganisms is valuable in that it has genetic and economic, scientific and cultural, social and recreational, and most importantly, ecological significance. After all, the diversity of animals and plants makes up the natural world that surrounds us everywhere, so it must be protected. People have already done irreparable damage that cannot be repaired. For example, many species were destroyed all over the planet:

Quagga

Sylph

Solving the problem of biodiversity conservation

In order to preserve biodiversity on earth, you need to make a lot of efforts. First of all, it is necessary that the governments of all countries pay special attention to this problem and protect natural objects from the encroachments of various people. Also, various international organizations, in particular, Greenpeace and the UN, are working to preserve the world of flora and fauna.

Among the main measures that are being taken, it should be mentioned that zoologists and other specialists are fighting for each individual of an endangered species, creating reserves and natural parks where animals are under observation, creating conditions for them to live and increase populations. Plants are also artificially bred to increase their ranges, to prevent valuable species from dying.
In addition, it is necessary to carry out measures to preserve forests, protect water bodies, soil and atmosphere from pollution, and apply them in production and everyday life. Most of all, the preservation of nature on the planet depends on ourselves, that is, on each person, because only we make a choice: to kill an animal or keep it alive, cut down a tree or not, pick a flower or plant a new one. If each of us will protect nature, then the problem of biodiversity will be overcome.

Biological diversity (biodiversity) is a concept that refers to the diversity of life on Earth and all existing natural systems. Biodiversity is recognized as one of the foundations of human life. The role of biodiversity is enormous - from stabilizing the earth's climate and restoring soil fertility to providing people with products and services, which allows us to maintain the well-being of society, and, in fact, allows life to exist on Earth.

The diversity of living organisms around us is very significant, and the level of knowledge about it is still not great. Today, science knows (described and received scientific names) about 1.75 million species, but it is estimated that at least 14 million species may exist on our planet.

Russia has significant biodiversity, while the unique feature of our country is the presence of large underdeveloped natural areas, where most of the ecological processes retain their natural character. Russia owns 25% of all virgin forests on the planet. In Russia, there are 11,500 species of wild plants, 320 species of mammals, 732 species of birds, 269 species of freshwater fish, and about 130,000 species of invertebrates. There are many endemics, species living only on the territory of our country. Our forests make up 22% of all forests in the world.

It is the topic "The role of diversity in wildlife" that this essay is devoted to.

1.

It is obvious to any of us that we are all different and that the world around us is diverse. However, not everyone would think to ask a seemingly simple question - why is this so? Why do we need diversity and what role does it play in everyday life?

And if you think about it seriously, it turns out that:

Diversity is progress, development, evolution. Something new can only be obtained from different things - atoms, thoughts, ideas, cultures, genotypes, technologies. If everything around is the same, then where does the new come from? Imagine that our Universe consists only of identical atoms (for example, hydrogen) - how could you and I be born at the same time?

Diversity is sustainability. It is the mutual and coordinated actions of components with different functions that give any complex system the ability to resist external influences. A system of identical elements is like pebbles on a beach - it is stable only until the next incoming wave.

Diversity is life. And we live in a series of generations solely due to the fact that we all have different genotypes. It is no coincidence that from time immemorial all religions of the world have imposed the strictest taboo on marriages with close relatives. This preserved the genetic diversity of the population, without which there is a direct path to degeneration and disappearance from the face of the earth.

If we now imagine that diversity has disappeared in the world, then with it we will lose:

A) the ability to develop;

B) stability;

c) life itself.

Creepy picture, isn't it?

That is, having asked a seemingly naive question, we come to an unexpected conclusion for many: variety - defining factor in the existence of all life on our planet.

Mankind, which imagines itself to be the "kings of nature", easily, without hesitation, wipes off the face of the earth "objectionable" species to us. We destroy entire species of plants and animals - completely, irrevocably, forever. We are destroying natural diversity and at the same time investing huge sums in cloning - the artificial creation of identical individuals ... And we call this biotechnology, the science of the future, with which we associate all hopes for further existence. What are the prospects for such an existence is clear from the previous paragraph - do not be lazy, re-read it again ...

At one time, we felt on ourselves both the “only true doctrine”, and the “society of universal equality”, and at the cost of millions of lives we were like “in a single ranks” ... In the socio-economic sphere, life has taught us to appreciate diversity, but is it necessary to go through even more ordeals to learn to appreciate biological diversity?

Biodiversity is defined by the World Wide Fund for Nature (1989) as “the entire diversity of life forms on earth, the millions of species of plants, animals, micro-organisms with their gene sets, and the complex ecosystems that make up wildlife”. Thus, biodiversity should be considered at three levels. Biological diversity at the species level covers the entire range of species on Earth from bacteria and protozoa to the kingdom of multicellular plants, animals and fungi. On a smaller scale, biological diversity includes the genetic diversity of species, both from geographically distant populations and from individuals within the same population. Biological diversity also includes the diversity of biological communities, species, ecosystems formed by communities and the interactions between these levels For the continuous survival of species and natural communities, all levels of biological diversity are necessary, all of which are important for humans. Species diversity demonstrates the richness of evolutionary and ecological adaptations of species to different environments. Species diversity serves as a source of diverse natural resources for humans. For example, tropical rainforests, with their richest array of species, produce a remarkable variety of plant and animal products that can be used for food, construction, and medicine. Genetic diversity is necessary for any species to maintain reproductive viability, resistance to diseases, and the ability to adapt to changing conditions. The genetic diversity of domestic animals and cultivated plants is especially valuable to those working on breeding programs to maintain and improve modern agricultural species.

Community-level diversity is the collective response of species to different environmental conditions. The biological communities found in deserts, steppes, forests, and floodlands maintain the continuity of the normal functioning of the ecosystem by providing “maintenance” to it, for example, through flood control, soil erosion protection, air and water filtration.

Species diversity

At every level of biological diversity - species, genetic and community diversity, experts study the mechanisms that change or maintain diversity. Species diversity includes the entire set of species that live on Earth. There are two main definitions of the concept of species. First: a species is a collection of individuals that differs from other groups in one or another morphological, physiological or biochemical characteristics. This is the morphological definition of the species. Differences in DNA sequences and other molecular markers are increasingly being used to distinguish between species that are virtually identical in appearance (such as bacteria). The second definition of a species is a set of individuals between which there is free interbreeding, but there is no interbreeding with individuals of other groups (the biological definition of a species).

The inability to clearly distinguish one species from another due to the similarity of their characteristics, or the resulting confusion in scientific names, often reduces the effectiveness of species protection efforts.

Only 10–30% of the world's species have now been described by biologists, and many may become extinct before they are described.

Any biodiversity conservation strategy requires a good understanding of how many species there are and how those species are distributed. To date, 1.5 million species have been described. At least twice as many species remain undescribed, mainly insects and other tropical arthropods.

Our knowledge of the number of species is not accurate, since many non-showy animals have not yet come to the attention of taxonomists. For example, small spiders, nematodes, soil fungi and insects living in the crowns of tropical forest trees are difficult to study; various currents are found, but the boundaries of these areas are usually unstable over time.

These little-studied groups can number hundreds and thousands, even millions of species. Bacteria are also very poorly studied. Because of the difficulty in growing and identifying them, microbiologists have only been able to identify about 4,000 species of bacteria. However, research conducted in Norway on bacterial DNA analysis shows that more than 4,000 species of bacteria can be present in one gram of soil, and about the same number can be found in marine sediments. Such high diversity, even in small samples, implies the existence of thousands or even millions of as yet undescribed bacterial species. Modern research is trying to determine what is the ratio of the number of widespread species of bacteria compared to regional or narrow local species.

Genetic intraspecific diversity is often provided by the reproductive behavior of individuals within a population. A population is a group of individuals of the same species that exchange genetic information among themselves and give fertile offspring. A species may include one or more distinct populations. A population can consist of a few individuals or millions.

Individuals within a population are usually genetically distinct from one another. Genetic diversity is due to the fact that individuals have slightly different genes - sections of chromosomes that encode certain proteins. Variants of a gene are known as its alleles. Differences arise from mutations - changes in the DNA that is located on the chromosomes of a particular individual. Alleles of a gene can affect the development and physiology of an individual in different ways. Breeders of plant varieties and animal breeds, by selecting certain gene variants, create high-yielding, pest-resistant species, such as crops (wheat, corn), livestock and poultry.

Diversity of communities and ecosystems

A biological community is defined as a collection of individuals of different species living in a certain area and interacting with each other. Examples of communities are coniferous forests, tall grass prairies, tropical rainforests, coral reefs, deserts. A biological community together with its environment is called an ecosystem. In terrestrial ecosystems, water is evaporated by biological objects from the surface of the Earth and from water surfaces in order to shed again in the form of rain or snow and replenish the terrestrial and aquatic environments. Photosynthetic organisms absorb light energy, which is used by plants for their growth. This energy is absorbed by animals that eat photosynthetic organisms or is released in the form of heat both during the life of organisms and after their death and decomposition.

The physical properties of the environment, especially the annual temperature and precipitation regime, influence the structure and characteristics of the biological community and determine the formation of either a forest, or a meadow, or a desert or a swamp. The biological community, in turn, can also change the physical characteristics of the environment. In terrestrial ecosystems, for example, wind speed, humidity, temperature and soil characteristics can be influenced by the plants and animals that live there. In aquatic ecosystems, such physical characteristics as turbulence and transparency of water, its chemical characteristics and depth determine the qualitative and quantitative composition of aquatic communities; and communities such as coral reefs themselves greatly influence the physical properties of the environment. Within a biological community, each species uses a unique set of resources that constitutes its niche. Any niche component can become a limiting factor when it limits the size of a population. For example, populations of bat species with highly specialized environmental requirements that form colonies only in limestone caves may be limited by the number of caves with suitable conditions.

The composition of communities is largely determined by competition and predators. Predators often significantly reduce the number of species - their prey - and may even displace some of them from their usual habitats. When predators are exterminated, the population of their prey can rise to a critical level or even exceed it. Then, after the exhaustion of the limiting resource, the destruction of the population may begin.

The community structure is also determined by symbiotic (in the broadest sense of the word) relationships (including mutualistic ones), in which species are in mutually beneficial relationships. Mutualistic species achieve greater density when living together. Common examples of such mutualism are plants with fleshy fruits and birds that feed on these fruits and spread their seeds; fungi and algae, which together form lichens; plants that give shelter to ants, supplying them with nutrients; coral polyps and the algae that live in them.

Tropical rainforests, coral reefs, vast tropical lakes and deep seas are the most species-rich. The biological diversity is also great in dry tropical regions with their deciduous forests, bush bushes, savannahs, prairies and deserts. In temperate latitudes, shrub-covered territories with a Mediterranean type of climate are distinguished by high rates. They are found in South Africa, southern California and southwestern Australia. Tropical rainforests are primarily characterized by an exceptional diversity of insects. On coral reefs and in deep seas, diversity is due to a much wider range of taxonomic groups. The diversity in the seas is associated with their great age, gigantic areas and the stability of this environment, as well as with the peculiarity of the types of bottom sediments. The remarkable diversity of fish in large tropical lakes and the emergence of unique species on islands is due to evolutionary radiation in isolated productive habitats.

The species diversity of almost all groups of organisms increases towards the tropics. For example, Thailand has 251 species of mammals, while France has only 93, despite the fact that the areas of both countries are approximately the same.

2. DIVERSITY OF LIVING ORGANISMS IS THE BASIS OF THE ORGANIZATION AND STABILITY OF THE BIOSPHERE

The biosphere is a complex outer shell of the Earth, inhabited by organisms that together make up the living substance of the planets. It can be said that the biosphere is an area of ​​active life, covering the lower part of the atmosphere, the upper part of the lithosphere and the hydrosphere.

Huge species diversity. living organisms provides a constant mode of biotic circulation. Each of the organisms enters into specific relationships with the environment and plays its role in the transformation of energy. This has formed certain natural complexes, which have their own specifics depending on environmental conditions in one or another part of the biosphere. Living organisms inhabit the biosphere and are included in one or another biocenosis - spatially limited parts of the biosphere - not in any combination, but form certain communities of species adapted to cohabitation. Such communities are called biocenoses.

The relationship between predator and prey is particularly complex. On the one hand, predators, destroying domestic animals, are subject to extermination. On the other hand, predators are necessary to maintain the ecological balance (“Wolves are the orderlies of the forest”).

An important ecological rule is that the more heterogeneous and complex the biocenoses, the higher the stability, the ability to withstand various external influences. Biocenoses are distinguished by great independence. Some of them persist for a long time, others regularly change. Lakes turn into swamps - peat is being formed, and as a result, a forest grows on the site of the lake.

The process of regular changes in the biocenosis is called succession. Succession is a successive change of some communities of organisms (biocenoses) by others in a certain area of ​​​​the environment. In a natural course, succession ends with the formation of a stable community stage. In the course of succession, the diversity of the species of organisms that make up the biocenosis increases, as a result of which its stability increases.

The increase in species diversity is due to the fact that each new component of the biocenosis opens up new opportunities for invasion. For example, the appearance of trees allows species living in the subsystem to penetrate into the ecosystem: on the bark, under the bark, building nests on branches, in hollows.

In the course of natural selection, only those types of organisms that can reproduce most successfully in this particular community are inevitably preserved in the composition of the biocenosis. The formation of biocenoses has an essential side: "competition for a place under the sun" between different biocenoses. In this “competition”, only those biocenoses are preserved that are characterized by the most complete division of labor between their members, and, consequently, richer internal biotic connections.

Since each biocenosis includes all the main ecological groups of organisms, it is equal in its capabilities to the biosphere. The biotic cycle within the biocenosis is a kind of reduced model of the Earth's biotic cycle.

Thus:

1. The stability of the biosphere as a whole, its ability to evolve is determined by the fact that it is a system of relatively independent biocenoses. The relationship between them is limited to connections through non-living components of the biosphere: gases, atmosphere, mineral salts, water, etc.

2. The biosphere is a hierarchically constructed unity, including the following levels of life: individual, population, biocenosis, biogeocenosis. Each of these levels has a relative independence, and only this ensures the possibility of the evolution of the entire large macrosystem.

3. The diversity of life forms, the relative stability of the biosphere as a habitat and the life of individual species create the prerequisites for a morphological process, an important element of which is the improvement of behavioral responses associated with the progressive development of the nervous system. Only those types of organisms survived that, in the course of the struggle for existence, began to leave offspring, despite the internal restructuring of the biosphere and the variability of cosmic and geological factors.

3. THE PROBLEM OF CONSERVATION OF DIVERSITY IN NATURE AS A FACTOR OF SURVIVAL OF HUMANITY

At the turn of the third millennium, we bitterly state that as a result of anthropogenic pressure, especially in recent decades, the number of plant and animal species has sharply decreased, their gene pool has been depleted, the areas of the most productive ecosystems have been reduced, and the health of the environment is deteriorating. The constant expansion of the lists of rare and endangered species of biota in new editions of the Red Books is a direct evidence of this. According to some forecasts of leading ornithologists, by the end of the 21st century, every eighth bird species will disappear on our planet.

Awareness of the need to preserve all species from the kingdoms of fungi, plants and animals, as the basis for the existence and well-being of mankind itself, served as a decisive incentive for the development and implementation of a number of major international and national programs, as well as the adoption of fundamental interstate agreements in the field of environmental protection and monitoring, plant and the animal world. After the signing and subsequent ratification by more than 170 states of the International Convention on Biodiversity (1992, Rio de Janeiro), much more attention has been paid to the study, conservation and sustainable use of biological resources in all countries of the world. In accordance with the basic requirements of the Convention on Biological Diversity, which Russia ratified in 1995, it was necessary to provide "scientific support" for decision-making in the field of wildlife conservation in-situ and ex-situ. Everything related to the inventory, assessment of the state, conservation, restoration and rational use of flora and fauna requires a clear scientific justification. For the vast territory of Russia with its landscape diversity, multinational population, various traditions in the use of natural resources, a much more active development of fundamental research is necessary, without which, in principle, it is impossible to carry out an inventory and develop a coordinated strategy for the protection of all categories of biodiversity, at all its hierarchical levels.

The problem of biodiversity conservation is today one of the central problems of ecology, since life itself on Earth is compensated only with a sufficient variety of evolutionary material. It is thanks to biological diversity that the structural and functional organization of ecological systems is created, ensuring their stability over time and resistance to changes in the external environment. According to the figurative definition of Corr. RAS A.F. Alimova: “The whole set of biological sciences studies four main phenomena: life, organism, biosphere and biodiversity. The first three form a series from life (at the base) to the biosphere (above), the fourth penetrates the first three: without a variety of organic molecules there is no life, without a morphological and functional diversity of cells, tissues, organs, and in unicellular - organelles - there is no organism, without the diversity of organisms, there can be no ecosystems and no biosphere.” In this regard, it seems very logical to study biodiversity not only at the species level, but at the level of populations, communities, and ecosystems. As the anthropogenic impact on nature intensifies, ultimately leading to the depletion of biological diversity, the study of the organization of specific communities and ecosystems, as well as the analysis of changes in their biodiversity, becomes really important. One of the most important causes of biodiversity degradation is the underestimation of its real economic value. Any proposed options for biodiversity conservation are constantly losing competition with forestry and agriculture, the mining industry, since the benefits from these sectors of the economy are visible and tangible, they have a price. Unfortunately, neither the centrally planned economy nor the modern market economy could and cannot correctly determine the true value of nature. At the same time, a group of experts led by Robert Constatz (University of Maryland) identified 17 categories of functions and services of nature, among which were climate regulation, atmospheric gas composition, water resources, soil formation, waste processing, genetic resources, etc. The calculations of these scientists gave a total estimate of these functions of nature at an average of 35 trillion. dollars, which is twice the GNP created by mankind (18 trillion dollars a year). We still do not pay due attention to this area of ​​research to determine the value of biodiversity, which does not allow us to create a reliable economic mechanism for protecting the environment in the republic.

Among the priority areas of scientific research for the coming decades for the purposes of biodiversity conservation in the European North-East of Russia, the following should be highlighted:

— unification of existing and development of new methods for assessing and inventorying all components of biodiversity;

— creation of computer databases on biodiversity in the context of individual taxa, types of ecosystems, forms of use of biodiversity components, including databases on rare plant and animal species;

– development and implementation of the latest methods of taxonomy in the systematics and diagnostics of plants, animals, fungi and microorganisms;

– continuation of the inventory of the biota of the region, and especially in specially protected natural areas;

— preparation and publication of new regional floristic and faunal reports, atlases, catalogs, guides, monographs on individual taxa of microorganisms, fungi, lower and higher plants, vertebrates and invertebrates;

— development of methodological foundations for the economic assessment of biodiversity;

— development of scientific bases and technologies for the restoration of biological diversity in anthropogenically disturbed terrestrial, water and soil ecosystems; — preparation of a regional program for the conservation of biodiversity, taking into account the specifics of the diverse conditions of our country.

CONCLUSION

Mankind has recognized the great importance of biological diversity and its components by adopting the Convention on Biological Diversity on June 5, 1992. It has become one of the most massive international conventions; today 187 countries are its members. Russia has been a party to the Convention since 1995. With the adoption of this Convention, a global approach to the conservation and sustainable use of the entire wealth of living organisms on Earth was adopted for the first time. The Convention recognizes the need for a multi-sectoral and integrated approach for the sustainable use and conservation of biodiversity, the special role of international information and technology exchange in this area, and the importance of fair and equitable sharing of benefits derived from the use of biological resources. It is these three components - sustainable use of biodiversity, conservation of biodiversity, equitable distribution of benefits from the use of genetic resources - that constitute the "three pillars" of the Convention.

The concept of biological diversity

The living organisms of our planet have gone through a long and complex path of development. In the course of evolution, changes occurred in the external and internal structure of living organisms, the system of relationships between groups of organisms, between organisms and the environment changed. As a result of natural selection, living organisms developed qualities that helped them survive in a changing environment.

The result of such a long evolutionary path was the diversity of representatives of the wildlife of our planet. They have different life forms, belong to different kingdoms.

To date, it has been proven that all living organisms have a single origin. This statement is supported by the unity of the chemical composition of living organisms, their cellular structure.

But at the same time, some living organisms are very different from others. Due to the presence of these differences, the biological diversity of the living matter of our planet has been formed.

Definition 1

Biodiversity is the totality of all forms and varieties of the organization of the living matter of the biosphere.

Reasons for biodiversity

The reason for biological diversity is the ability of living organisms to adapt to certain environmental conditions - the ability to adapt.

As a result of interaction with various environmental factors on Earth, various ecological groups of living organisms have formed:

• thermophilic,
• cold-resistant,
• light-loving,
• moisture-loving,
• drought-resistant,
• and so on.

In the process of competition for territory and food, living organisms led a different mode of existence - attached, freely moving, sedentary, migratory. Plants evolved life forms such as grasses, trees, and shrubs. With more detailed adaptation to environmental conditions, new species of plants, animals and microorganisms arose.

Summing up the above, we can conclude that the cause of biological diversity is the result of the constant interaction of living organisms and the environment. Recently, human activities have had a great impact on biodiversity.

Types of biodiversity

When considering biodiversity, attention is most often paid to such aspects as genetic, species and ecosystem.

Definition 2

genetic biodiversity is a set of gene pools of different populations of the same species.

To ensure genetic biodiversity, it is necessary to create an ecological network. This will make it possible to preserve representatives of the species not only in individual protected areas (in reserves), but also throughout the entire territory of the distribution of the species.

Definition 3

Species diversity is the totality of all species inhabiting a certain area.

Man's task is to preserve all existing species. After all, the loss of at least one species is an irreversible process. Protected areas are created to preserve species diversity.

Definition 4

Ecosystem biodiversity (landscape) is a collection of unique and typical forest, mountain, swamp, steppe, marine, river communities of living organisms.

Ecosystems are the main object of nature protection activities. They form the biogeographic feature of each region of our planet.

The concepts of succession and agrocenosis

Biogeocenoses are a self-regulating system. Therefore, in the process of development of biogeocenosis, its species diversity also changes.